1. Field
The following description relates to a zoom optical system to adjust a focal length.
2. Description of Related Art
A zoom optical system has an adjustable focal length. For example, the focal length of a zoom optical system is adjusted so as to clearly capture an image of an object at a long distance or an object at a short distance. Such a zoom optical system commonly includes lenses made of glass to decrease chromatic aberrations.
Over time, a camera module including the zoom optical system has been gradually miniaturized in size over the years. Therefore, miniaturization of the zoom optical system has also been required. However, because manufacturing costs of zoom optical systems containing lenses made of glass are relatively high and it is difficult to produce zoom optical systems that are light weight, it is difficult to apply zoom optical systems containing lenses made of glass to a small camera. Therefore, the development of a lightened zoom optical system able to be mounted in a small camera module is needed.